Technical Field
This disclosure relates to a circuit board inspecting apparatus and a circuit board inspecting method for conducting an inspection on a circuit board.
Related Art
A circuit board having a plurality of wiring patterns formed thereon has been subjected to an insulation inspection (a leak inspection) as to whether or not the respective wiring patterns are correctly insulated from one another. The insulation inspection involves applying a voltage between wiring patterns to be inspected, and detecting a current flowing between the wiring patterns. However, if an insulation failure occurs between the wiring patterns, the current flows through a portion where the insulation failure occurs, at the time when the voltage for use in the insulation inspection is applied between the wiring patterns. As a result, heat is generated to cause burnout of the portion where the insulation failure occurs.
In view of this circumstance, a known technique involves: applying, between wiring patterns, a low voltage which does not cause burnout of a portion where an insulation failure occurs; applying a high voltage between wiring patterns between which no current flows in the insulation inspection using the low voltage; and determining the wiring patterns between which no current flows in the insulation inspection using the high voltage, as wiring patterns between which no insulation failure occurs (i.e., as wiring patterns which are favorably insulated from each other) (refer to, for example, JP 06-230058 A).
However, the inventors have newly found that the inspecting method disclosed in JP 06-230058 A erroneously determines wiring patterns between which an insulation failure occurs, as wiring patterns which are favorably insulated from each other (i.e., the inspecting method is incapable of detecting an insulation failure).